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Walter Roberson


Last seen: Today Active since 2011

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location. I am currently caught up to T0099000; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C++, C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

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Answered
Error using imread>get_full_filename (line 569) File "cameraman.tif" does not exist.
Perhaps you do not have the Image Processing Toolbox installed.

1 hour ago | 0

Answered
what error in classification code ?
Incorrect input size. The input images must have a size of [64 64 1]. That is telling you that your input images are some size ...

2 hours ago | 0

Answered
How can i programe this function without rem or mod?
a = 1 : 25 d = randi([2 15]) t = int32(a) - int32(a) / int32(d) * int32(d); t(t < 0) = t(t<0) + d int32(mod(a, d))

3 hours ago | 0

Answered
unable to resolve the name vision.CascadeObjectDetector
You need to have the Computer Vision Toolbox licensed and installed. (And you need to be using R2012a or later.)

4 hours ago | 0

Answered
To use 'awgn', the following product must be both licensed and installed: Communications System Toolbox
Ok, so make sure you have Communications System Toolbox registered for your license, and then install the toolbox.

4 hours ago | 0

Answered
How do I return a single specific toolbox license so that someone else in my company can use it?
Mathworks Support can work with your license administration person to move the license. If I recall correctly, you might need...

4 hours ago | 0

| accepted

Answered
How to convert a symbolic output signal to double precision for plotting
Your ilaplace() functions are going to be in terms of t at least, and possibly other symbolic variables as well. If you have a ...

10 hours ago | 0

Answered
How can i convert my user class object into a mex file?
You cannot use MATLAB Coder to convert a class method into a mex file. You can only convert functions outside of classes. This...

12 hours ago | 0

Answered
Calculate delta time in seconds
SaT = datetime(DataaBaseA.Starttime, 'InputFormat', 'dd-MMM-yyyy HH:mm:ss'); StT = datetime(DataaBaseA.Stoptime, 'InputFormat'...

12 hours ago | 1

| accepted

Answered
matlab online supports reading local files?
@cui I do not think that is likely to happen. MATLAB Online only has whatever access to local drives that javascript sent to th...

12 hours ago | 0

Answered
graphing norm of residuals
You can create an options structure that specifies PlotFcn https://www.mathworks.com/help/matlab/math/plot-functions.html You ...

12 hours ago | 0

Answered
Why would command syntax split string when using double quotes?
Not exactly. The latter is equivalent to disp('"str', 'ing"') N 'str ing' N "str ing" function N(varargin) fprintf('nar...

13 hours ago | 0

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Answered
Greek letter variables explication
There is currently no way to create datatips for variables.

13 hours ago | 0

Answered
How can I change color of a circle?
imageSizeX = 256; imageSizeY = 256; [Imagecolumns, Imagerows] = meshgrid(1:imageSizeX, 1:imageSizeY); Right_X = imageSize...

13 hours ago | 0

| accepted

Answered
Merge multiple XLSX files with one header mismatch
https://www.mathworks.com/help/matlab/ref/table.movevars.html %% IMPORT D = '/Users/nda/Documents/Helmet/Cube/Data/C2/Impacts...

14 hours ago | 1

Answered
fminsearch to fit data
You cannot pass two variables and two equations to fit to fminsearch() fminsearch() can work with a vector of variables, but on...

14 hours ago | 0

| accepted

Answered
how to solve Index exceeds the number of array elements (1)?
codebook = 0; % Vo + all remaining quantisation levels in an array e.g. codebook = [Vo V1 V2 V3 etc...]; Look at the comments. ...

14 hours ago | 0

Answered
how to filter particular set of dates from a column?
idx = find(19800310 <= column & column <= 19901214); At this point you can select corresponding values by selected_data = Your...

15 hours ago | 0

Answered
请问“最初保存为treebagger的变量无法实例化为对象”是为什么?
That error message would occur if your system does not have the class definition for treebagger . In particular, it would occur ...

16 hours ago | 0

Answered
Matlab not reading data fast enough from arduino.
analogRead() returns an integer value in the range 0 to 1023. My calculation is that the mean number of digits required to repre...

16 hours ago | 1

Answered
Whitespace Delimited Textfile, NaN results?
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/781593/test.txt'; datavalues = readmatrix(filename)

17 hours ago | 1

Answered
fir1 in R2021b vs R2017
I just tested with R2017a and R2021b on my system. The results were bit-for-bit identical between the two systems. Question: do...

17 hours ago | 0

Answered
Invalid use of operator error - GUI
You have % --- Executes on button press in Auto. function pushbutton_auto_Callback(hObject, eventdata, handles) % hObject ...

1 day ago | 0

Answered
How to decide the number of workers by seeing computer specs like CPUS or Cores or threads?
By examination of your code, we can see that if any worker is scheduled for N iterations of the work, that it must take approxim...

1 day ago | 0

Answered
Analyzing a Large Amount of Data in a CSV file
The line eval('cntry' string(j) '=A'); is the problem. You have a character vector, then a space, then a string scalar...

1 day ago | 0

Answered
How to solve "File: first.m Line: 1 Column: 1 Invalid use of operator" error?
That is C code. It cannot be run directly from MATLAB. To call it from MATLAB, you would need to compile it, and then use loadl...

1 day ago | 0

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Answered
'simulink' requires Simulink. Error
Your account is not licensed for Simulink. Note: the basic Student license (about $US50) does not include Simulink as part of t...

1 day ago | 0

Answered
How can another person use my student licence?
You can only install MATLAB on a computer that you own or lease. You would only be permitted to install MATLAB on someone else's...

1 day ago | 0

Answered
I would like to remove zeros from my matrix
a = [0 0 0; 0 0 0; 1 2 3; 4 5 6] b = rmmissing(standardizeMissing(a, 0))

1 day ago | 0

Answered
How to read a txt file with comma, text and numbers in matlab, and export the data
http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F See also readtable()

1 day ago | 1

| accepted

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